1. Field of the Invention
Embodiments of the invention generally pertain to the field of optical imaging, more particularly to endoscopic apparatus/systems that can simultaneously acquire lower field of view (FOV), higher resolution images and wider FOV, lower resolution images and, most particularly to single, multi-focal optical components that enable simultaneous lower FOV, higher resolution imaging and wider FOV, lower resolution imaging, and use of such components in endoscopes and particularly multi-photon endoscopes (MPEs).
2. Description of Related Art
Multiphoton microscopy (MPM) is a powerful tool for biological imaging. It enables minimally invasive imaging of endogenous fluorescent species and harmonic generation, providing contrast in unstained tissues. By incorporating a miniaturized endoscope, medical multiphoton microscopic endoscopy (MPM-E) could play a significant role in, e.g., clinical cancer diagnosis. As presented in previous reports of multiphoton microscopic endoscopes (Jung & Schnitzer 2003; Wu et al 2009), MPM-E can facilitate noninvasive diagnosis of a diseased state in-situ, potentially becoming a valuable technology for clinical diagnosis.
A significant obstacle to the development of a practical MPM-E probe has been the need for optical zooming capability. During clinical diagnosis, low-magnification and large field of view (FOV) imaging would allow clinicians to survey a large area and locate the disease site and then perform high-resolution multiphoton imaging to confirm the diagnosis. For practical implementation, both the large FOV imaging and high-resolution imaging must be obtained with the same endoscope apparatus. While such an optical zooming capability is easily accomplished with conventional microscopes by using multiple objective lenses, achieving the same capability in a compact endoscope presents a significant challenge. Previous fiber based MPM-E designs (Jung & Schnitzer 2003; Wu et al. 2009; Fu et al. 2005; Le Harzic et al. 2008) utilized either monolithic components, such as gradient refractive index (GRIN) lenses, or compound lens assemblies. However, these endoscope probes do not provide optical zooming capability, although by scanning a small area using a galvo mirror or fiber scanner, magnified images could be obtained. This magnification, however, does not change optical resolution. Therefore, previous systems were limited to performing either high-resolution imaging with a small FOV or low-resolution imaging with a large FOV.
In view of the foregoing problems and disadvantages in the prior art, the inventors have recognized the need for a solution to these issues and the benefits and advantages, that could be realized by an optical component, a system incorporating said component (e.g., a multi-photon endoscope (MPE)), methods and applications of such apparatus and methods that would overcome the known shortcomings in the art.